Any of the various now-extinct species of large mammals related to elephants. It looked like a stocky, long elephant, had long reddish-brown hair, and shorter, straighter tusks than the mammoth. The American mastodon (Mammut americanum), is classified as a browser from its low-crowned teeth, as opposed to the woolly mammoth (Mammuthus primigenius), which because of its high-crowned teeth, is classified as a grazer. It lived on spruce and pine. The mastodon had large hemispherical cusps on the surface of each molar tooth. They first appeared in the early Miocene and continued in various forms through the Pleistocene Epoch (from 1,600,000-10,000 years ago). In North America, mastodons probably persisted into post-Pleistocene time and were contemporaneous with historic North American Indian groups. Mastodons had a worldwide distribution; their remains are quite common and are often very well preserved. Hunting may have led to its extinction.